1. Technical Field
Aspects of the present invention relate to a sheet feeding device configured to feed a sheet along a predetermined sheet feed path, and an image scanning device employing such a sheet feeding device.
2. Prior Art
An image scanning device provided with an ADF (Automatic Document Feeders), and an openable/closeable sheet feed trays on which originals are placed has been known.
The conventional image scanning device as described above is configured such that the sheet feed tray is rotatable (mostly foldable) with respect to a housing thereof such that the sheet feed tray is rotated to close a sheet inlet when the ADF is not used.
Between the sheet inlet and the sheet feed tray, a sheet passing surface, which is provided with side regulation members, is formed. An area from the sheet passing surface to the sheet feed tray is used as a sheet placing surface on which the original sheet subjected to be fed by the ADF is placed.
When the sheet placing surface is formed with two members such as the sheet feed tray and the sheet passing surface described above, if there is a step or a gap at a border between the two members, a leading end of the original sheet may be hooked at the step or a gap depending on the shape thereof when the original sheet is fed.
Specifically, if a step is formed as the sheet feed tray is arranged lower than the sheet passing surface at the border therebetween, and the original sheet placed on the sheet feed tray is fed to the sheet inlet via the sheet passing surface, the leading end of the original sheet may be hooked easily at the step. If there is a gap instead of the step, the original sheet may enter the gap and may also be hooked.
If the sheet feed tray is arranged higher than the sheet passing surface at the border, a stepped surface formed therebetween does not face the leading end of the sheet. Therefore, in such a case, the original sheet may not be hooked when fed to the sheet inlet.
The similar problem occurs on the sheet discharging side. For example, when the original sheet is discharged from a sheet outlet and fed to a sheet discharge tray via a sheet passing surface, if the sheet passing surface is arranged lower than the sheet discharge tray at the border therebetween, the leading end of the sheet can easily be hooked by the step or gap therebetween.
If the sheet passing surface is arranged higher than the sheet passing surface at the border, a stepped surface formed therebetween does not face the leading end of the sheet. Therefore, in such a case, the original sheet may not be hooked when fed out of the sheet outlet.
As above, it is possible to avoid the problem that the leading end of the sheet is hooked by the stepped portion at the border between two discontinuous surfaces by optimizing the direction of the stepped surface depending on a sheet feeding direction.
Recently, there is a requirement that a single tray is used either as the sheet feed tray or the sheet discharge tray instead of using sheet feed tray and sheet discharge tray separately. When the same tray is used for the both purposes, it is difficult to optimize the direction of the stepped surface referring to the sheet feeding direction.
Specifically, the applicant is considering to employ a feeding device which is configured such that an original sheet is placed on a single sheet feed/discharge tray, the original sheet is fed by an ADF, and the original sheet having been fed is discharged on the sheet feed/discharge tray.